New Oplopane‐Type Sesquiterpenes from Ligularia narynensis

Four new, highly oxygenated oplopane‐type sesquiterpenes ( 3 – 6 ) were isolated from the roots of Ligularia narynensis, together with four known compounds, and their structures were elucidated by spectroscopic methods and comparison with literature data. Selected congeners were evaluated for their in vitro cytotoxic activities against cultured SMMC‐7721 (human hepatoma), L02 (human hepatocyte), and HL‐60 (human promyelocytic leukemia) cells, but were found to be inactive.